Doors forming entranceways into houses and other buildings, and even into individual rooms in buildings, are often provided for installation already "pre-hung" in a door frame (also referred to herein as a "frame"). Doors and corresponding frames may further be provided in both standard and custom sizes and configurations. Pre-hanging the door in a frame means that the hinges and the locking device (or openings therefor) are already aligned and/or installed between the door and the frame. Thus, the frame merely needs to be placed in a framed opening in the proper location and secured in place for the door to be a functional entranceway. No further alignment of the door within the frame is required. Thus, a pre-hung door comprises a convenient and time saving means for installing a door in a building.
A door frame typically includes an outer molding on one edge of the frame, forming a lip generally around the top and the sides thereof. The framed opening in which the frame is inserted is constructed of interconnected framing members configured to generally accommodate the outer dimensions of the frame. One face of the framed opening thus defines part of the outer wall of the room or building and the other face defines part of the inner wall. Installation of the pre-hung door in the framed opening generally comprises sliding the frame into the framed opening such that the outer molding lip fits flush with the outer wall side of the framed opening. The frame is then shimmed into proper alignment within the framed opening. A molding is then attached to the inner wall side of the framed opening, typically covering the top and both sides of the frame and extending between the frame and the framed opening. A lip is thereby formed on the inner wall side of the framed opening, opposing the lip formed by the outer molding, securing the frame in the framed opening.
While the frame is generally secured within the framed opening by the outer molding and the opposing inner molding, the door itself is attached only to the frame. That is, the door hinges and the strike plate are attached to the frame by fasteners, wherein the hinges are attached to the hinge jamb and the strike plate is attached to the strike jamb. The hinges attach to the door and allow the door to swing open and closed within the frame. The strike plate engages the door by accommodating the locking element of the locking device when the door is in the closed position. Usually, however, a typical door has three hinges, but only one locking device (thus only one strike plate on the strike jamb with which to engage). This typical door configuration presents a problem where entry into a building or a room is being attempted by force, i.e. in the event of a break-in.
Where a door is being kicked or battered in the event of a break-in using forced entry, the hinge side of the frame generally has three hinges connected between the door and the hinge jamb over which to distribute the force applied against the door. On the other hand, the force on the strike plate side of the frame is concentrated in the vicinity of the strike plate on the strike jamb. Thus, the strike jamb is most likely to fail from the force applied to the door, rather than the hinge jamb. More specifically, where the strike jamb is made of a soft material such as wood, aluminum, or thin metal, the strike jamb is likely to splinter, deform, or break in the vicinity of the strike plate, thus allowing the door to open. However, it is also possible, since the hinges are just screwed into the frame, for the screws securing the hinges to strip out of the hinge jamb or for the hinge jamb to fail, thus causing the hinge side of the door to fail. Due to these shortcomings with pre-hung doors, a number of attempts have been made to increase the resistance of door frames to breaking forces applied thereto.
For example, U.S. Pat. No. 5,241,790 to Schimpf discloses a kick-proof door jamb reinforcing means and assembly comprising a reinforcing plate mounted in back of the door jamb on the strike plate side in the space between the jamb and the framed opening. Shims are used to temporarily jam the plate between the already installed door jamb and the framed opening while a drill is used to drill directly through the face of the door jamb into the plate at locations at which it is desired to secure the plate to the door jamb. Self-tapping one-way fasteners are then threaded through the bores drilled in the door jamb directly into the plate where they thread into the plate and hold it securely against the door jamb. Openings are also drilled through the strike plate screw holes directly into the reinforcing plate and the strike plate is then secured firmly to the plate by self-tapping screws, machine bolt fastenings, or special fastenings to provide metal-to-metal contacts between the parts.
While the '790 patent provides a reinforcing means for a door jamb, it addresses only the strike plate side of the door frame. As previously discussed, with a pre-hung door, the hinges are usually attached only to the door frame. The fasteners securing the hinges do not pass into the framing members forming the framed opening. By reinforcing only the strike jamb and not the hinge jamb, the hinge jamb becomes a weak point on the frame and therefore more likely to fail when force is being applied to break open the door. Further, the '790 patent discloses that the reinforcing plate is attached solely to the back of the strike jamb by fasteners passing through the jamb and into the plate. The fasteners do not extend into the adjacent framing members. The plate is inserted into the space between the framed opening and the frame after the frame has been installed in the framed opening. Once the plate is wedged into place, holes in the jamb and plate must then be drilled before self-tapping screws are installed in the jamb to secure the plate therebehind. The strike plate is then attached to the strike jamb with self-tapping screws passing through the holes in the strike plate, the jamb, and into the plate. Thus, the installation of the reinforcing plate according to the '790 patent comprises securing the reinforcing plate only to the back of the strike jamb. Further, since the plate is only wedged into place while the installation holes are drilled and not securely fastened to the back of the jamb, the plate may shift between the drilling of successive holes for installing the plate. In addition, with most doors, the frame is secured within the framed opening by just the opposing moldings, whereby entry into the building/room may still be gained by removing the outer molding around the outside of the door frame. By forcing the frame inward after the outer molding is removed, the frame can drop out of the framed opening since the frame is not secured within the framed opening by fasteners passing through the frame and into adjacent framing members.
In another example, U.S. Pat. No. 4,770,452 to Petree, Jr. discloses a concealed door frame security device comprising an elongated rigid plate inserted into a slot and firmly anchored in place in the door jamb in spaced parallel relation to the free vertical edge of the door. The plate is provided with an opening aligned with an opening in the door jamb, and the spacing between the plate and the face of the door jamb is such that the locking element will project through the aligned openings in the door jamb and the plate. The slot is formed by routing the door jamb intermediately between its inner surface and an offset surface portion and to a depth extending beyond the offset surface portion into the wider portion of the door jamb. To anchor the plate within the slot, openings are formed at spaced intervals along the length of the plate and adapted to receive threaded fasteners in the form of wood screws which are threaded through the door jamb offset surface section, the openings in the plate, and into the stud members forming the framed opening and surrounding the door frame.
The '452 patent provides a concealed means for a reinforcing a door jamb. However, the apparatus disclosed by the '452 patent addresses only the strike plate side of the frame. Further, in order to install the reinforcing plate in the frame, a slot must be routed into the frame to accommodate the plate. Once inserted into the slot in the frame, the plate is fastened therein by fasteners extending through the door jamb, pre-drilled holes in the plate, through the remainder of the door jamb, and into the adjacent framing member. The plate further contains pre-cut openings for engaging locking devices attached to the door. Thus, the apparatus disclosed by the '452 patent can be difficult to install because of the routing or milling of the door frame which is required to form the slot into which the plate is inserted. Further, drilling installation holes through the door jamb to correspond with the pre-drilled holes in the plate can also be difficult, especially since the plate is not securely attached to the jamb within the slot and may shift between the drilling of successive holes. In addition, the pre-cut openings in the plate which engage the locking device(s) must be precisely aligned with the pre-existing openings in the door jamb in order for the locking devices to function as intended.
In another example, U.S. Pat. No. 3,918,207 to Aliotta discloses a door frame protector comprising a plate adapted for attachment to the hidden outer face of an upstanding frame side member and a flange adapted for engagement with the inside edge of the frame side member. This device is formed from a generally rectangular sheet of rigid material having one edge turned up generally perpendicular to the sheet, forming the flange. The door frame protector is arranged so that the plate engages the concealed outer surface of the side member and the flange is mortised into the inside edge of the side member. The door frame protector is attached to the frame side member either by screws passing through the protector into the side member or by screws passing through the side frame to engage with threaded holes in the protector.
The '207 patent discloses a door frame protector which comprises an L-shaped plate installed between the strike jamb and the framed opening for reinforcing the jamb. The apparatus disclosed by the '207 patent also addresses only the strike plate side of the frame. While the plate is just inserted between the back side of the strike jamb and the adjacent framing member, the inside edge of the jamb must be milled or mortised in order for the flange to fit flush therewith. In addition, the plate is attached only to the jamb either by screws passing through the plate into the jamb or by screws passing through the jamb to engage with threaded holes in the plate. As such, entry into the building/room may still be gained by dismantling the outer molding around the outside of the frame and forcing the frame inward. Since the frame is not secured to the adjacent framing members, the frame can drop out of the framed opening, allowing entry into the building/room. Further, where fasteners pass through the jamb to engage with pre-threaded holes in the plate, drilling holes through the jamb to correspond with the holes in the plate can be difficult, especially since the plate is not securely attached to the jamb and may shift between the drilling of successive holes. Another aspect of the apparatus disclosed by the '207 patent is that the screws securing the strike plate to the strike jamb do not engage the plate. As such, should the flange deform or fail in the event that force is applied to the door, the strike plate is not otherwise tied to the reinforcing plate and the strike jamb will therefore also fail.
In still another example, U.S. Pat. No. 5,566,509 to Long discloses a door jamb reinforcing strip comprising an elongated strip having an L-shaped transverse cross-section comprising one short leg and one long leg, the long leg for mounting on a door jamb face and the short leg for mounting on a door jamb edge. The long leg includes a plurality of openings spaced over the entire length of the strip and is adapted to seat screws or receive a door latch tongue therein. The short leg of the strip has a transverse extent which is no greater than the offset distance between the door jamb face and the forward edge of the door casing panel, such that when the long leg of the reinforcement strip is mounted on the door jamb face, the short leg of the reinforcement strip is mounted flush with the door jamb edge and is in contact with or slightly spaced from the forward edge of the door casing. In sum, the reinforcement strip forms an interior corner that is adapted to fit over an outside vertical corner of a door jamb and form a reinforcement therefor. The reinforcement strip is secured to the door jamb by a plurality of long wood screws which extend through the door jamb, through a spacer, and into the adjacent wall stud forming part of the framed opening.
The '509 patent discloses an L-shaped reinforcing strip for a door jamb wherein the strip includes pre-formed openings to engage the locking element attached to the door. The strip is placed on the doorjamb such that the short leg of the strip wraps around the inner edge of the strike jamb. The strip is then attached to the jamb by fasteners passing through pre-drilled holes in the strip, the strike jamb, and into the adjacent framing member. However, the apparatus disclosed by the '509 patent addresses only the strike plate side of the door frame. Further, even though the strip may be effective in reinforcing the door frame, its installation on the front face of the strike jamb can make it aesthetically unappealing in some situations.
Thus, there exists a need for an apparatus for reinforcing a pre-hung door unit which comprises a door pre-aligned in a frame. It would be desirable for the apparatus to be concealable and easy to install without requiring milling, routing, or other machining of the frame. In addition, it would be desirable for the apparatus to address both the strike jamb and the hinge jamb and provide a means for reinforcing both. Further, it would be desirable for the apparatus to be able to accommodate varying strike plate and hinge locations without requiring modification of the apparatus or complex alignment thereof. It is also preferred that the apparatus be securable to the jambs such that subsequent installation steps may be performed without the apparatus shifting position. The apparatus should also preferably be able to accommodate multiple locking devices, each having a locking element engaging the strike jamb, without requiring modification or complex alignment thereof. In addition, it would be desirable for the apparatus to reinforce the frame while also reinforcing the connection between the door frame and the adjacent framing members forming the framed opening. In addition to the preceding preferences, the apparatus should also preferably be easily installable on new pre-hung door units before the units are installed, as well as readily adaptable for retrofitting and reinforcing door frames which have already been installed.